C.O.
M.:
If you have doubts - confront him. You are doing yourself no service by hanging on to this.
If you are checking his cell phone records, you aren't trusting him.
I don't know why you are STILL thinking over this. If your radar is pinging - then confront him. If you don't trust him - hire someone to track him to see what he is doing - if you don't feel that he will be honest with you about it.
I personally think you are making a mountain out of a mole hill and asking for trouble. If you keep pushing it - you may just push him away. If you think you have a strong marriage - then confront him and get it over with.